Electrical Systems, Energy Model, & PV

August 15th Meeting Recap: Those who spend time in the Lincoln School know that whether it’s summer or winter, currently there is a wide temperature range from one room to another. One of the big impacts of the renovation will be a better, quieter, and much more consistent environment for our students and faculty. The choice of HVAC (Heating, Ventilation, Air Conditioning), lighting, and life-safety systems also ties directly into our goal of making this an energy-efficient and sustainable building. This week’s SBC meeting was focused on three key components of the project: the electrical systems, predicted electricity needs, and on-site electricity generation. Click here for the slide presentation.

• HVAC: The goal is to try to move to all-electric systems and to generate as much energy as the school uses. Currently the school is heated with natural gas, and there is no centralized de-humidification or cooling (some selected areas such as offices and the library do have cooling). We are planning to switch to an electric system that will have the capacity to heat, de-humidify, and cool the building by using a Variable Refrigerant Flow (VRF) HVAC system. It is similar to a “mini-split” system used in many homes, and allows temperatures to be evenly controlled in different parts of the building. The system will also include energy recovery units that will provide ventilation throughout the building.
• Lighting: The project will include LED lighting and a straightforward digital lighting control system. This will adjust the level of artificial light to the amount of natural light in a room, helping to reduce energy consumption.
• Life-Safety: Communication systems, security, and fire protection systems are all part of the electrical system. What happens if we lose power?! An emergency generator is also part of the project to ensure operable safety systems, frozen pipe prevention, and communication in case of power loss.
• How Much Electricity Do We Need? As plans are developed, SMMA is developing and updating the energy model that predicts how much electricity will be needed to run the building. The current iteration of the model predicts the average annual use will be 1.1 million kWh. When planning for energy generation and operating costs, the industry best practice is to add 20% to the predicted use, which brings us to 1.3 million kWh/year. These numbers will continue to be refined throughout the design process.
• On-Site Electricity Generation: Good news – Between the roof of the school and building photovoltaic (PV) canopies over the two main parking lots, we can generate all the electricity we need! TBD – As presented by SMMA and Solar Design Associates, the current cost estimate (which is purposely conservative) is higher than the amount earmarked in the June budget. Click here for Solar Design Associates’ slide presentation.

Next Steps: SMMA and Solar Design Associates will continue to refine the building systems and the design, see how those changes affect the energy model, review cost estimates, and look for opportunities within the project budget for meeting our sustainability goals. The SBC will revisit this topic at an upcoming meeting.

This Wednesday’s Meeting (August 22nd):  The SBC will be meeting this Wednesday and will look again at site plans, exterior elevations, and plans for the central entrance and Commons. Please join us at 7:00pm in the Hartwell multipurpose room or watch us on TV! An updated meeting schedule can be be found here .